I've never been sure what to make of compression pedals. This one is no different. I bought this purely because of the price. They aren't terribly expensive.
My interest in compression is for sustain. That's about it. I can never quite tell if or when I've applied too much and I'd probably be lost in a 4 knob compression pedal.
I'm not in love with this.... I do think it can be noisy at times. But it does seem to work. If you don't know much about compression and want something simple and affordable, try this. If you are a compression guru, I'd guess you'll look elsewhere.